add support for ulimits in docker role

roles/docker/templates/docker-compose.yml.j2

@@ -25,6 +25,9 @@ services:
       - {{ cap }}
 {% endfor %}
 {% endif %}
+{% if container.ulimits is defined %}
+{{ container.ulimits | to_nice_yaml(indent=2) | trim | indent(4, true) }}
+{% endif %}
 {% if container.devices is defined %}
     devices:
 {% for device in container.devices %}